The present invention relates to a rotor of a directly gas-cooled electrical turbomachine, which rotor has at each axial end a respective gas guiding ring consisting of two gas guiding ring half shells, respectively connected to a cap plate of the rotor. It also relates to a process for the assembly of such a rotor.
The rotor cap, particularly in rotors of a turbogenerator with direct gas cooling, is known to undergo ovalization due to the centrifugal force which acts on it and on the windings lying therebeneath. This ovalization also relates to the cap plate and the gas guiding ring. Due to the pressure difference arising at the gas guiding ring half shells during operation of the turbogenerator, a known axial displacement results in known turbogenerators, and produces wear. Furthermore, during shaft rotation (rotational speed less than 40 rpm) of known turbogenerators, a tangential and radial movement of the gas guiding ring half shells arises, which leads to additional wear in the cap plate.
The invention thus has as its object to provide a rotor of a directly gas-cooled turbomachine, in which axial displacements of the gas guiding ring half shells and also tangential and radial movements of the gas guiding ring half shells are made impossible.
The rotor according to the invention is distinguished by fixing wedges, a respective one of which is inserted at the place of the separation between mutually opposing end sections of the gas guiding ring half shells, abuts on both sides on the end region sections, and is securely connected to the cap plate. Moreover, the rotor has a retaining ring consisting of two retaining ring halves, connected to the gas guiding ring and likewise connected to the cap plate, in order to position the gas guiding ring axially and radially with respect to the cap plate. The respective separation place of the gas guiding ring half shells is offset here by at least about 90xc2x0 from the respective separation place of the retaining ring halves.
The process is characterized in that the gas guiding ring half shells are inserted into the cap plate and pressed apart with respect to this, then the fixing wedges are fitted into the gaps between the mutually opposing end sections of the gas guiding ring half shells and are secured, the gas guiding ring half shells are released and the retaining ring halves are positioned on the gas guiding ring half shells, and finally the retaining ring halves are screwed to the cap plate.
The advantages of the invention are particularly that the retaining ring halves position the gas guiding ring half shells both axially and also radially, and simultaneously also, by means of the fixing wedges, absorb the tangential forces when a short circuit occurs. The retaining ring halves are held in a recessed region against the centrifugal forces. It is thus ensured that both in the stationary state and also during shaft rotation, the gas guiding ring half shells are fixed in every direction, so that no wear arises. However, the gas guiding ring half shells can accommodate the ovalization of the cap plate in operation.